The “host” tool can be used to query DNS entries and find the hostname of a server using the IP address. It comes default with the Ubuntu operating system, and it is available to any user. Below is an example of how to use it:
computer@computer:~$ host <ip_address>
Alternatively, you can use the “dig” command for more information
computer@computer:~$ dig <ip_address>
Both of these tools are useful for obtaining domain name information in ubuntu.